The plants grown by Wageningen University researchers in Mars-like soil back in March have been analyzed and the results are excellent: at least four of the crops do not contain harmful heavy metal levels and are perfectly safe to eat, the University researchers report.

    If you've seen The Martian, you can remember how much Matt Damon got done living off of his poo-powered crop of potatoes. It just goes to show how important it is for a long-term colony to be able to grow their own food locally. We've taken one step closer to that goal in March, when Netherlands' Wageningen University reported that they've managed to grow ten different crops in Mars-like soil.

    However, growing food doesn't do us much good if eating it kills us, and researchers were worried that these crops contained dangerous heavy metals like lead or cadmium(镉) from the martian soil. But future colonists are delighted, as lab analysis of the crops determined that at least four of them are safe to eat.

    Led by ecologist Wieger Wamelink, the team tested radishes, tomatoes, rye, and peas. They looked at cadmium, lead, aluminium(铝), nickel(镍), copper, chrome(铬), iron, arsenic(砷), manganese(锰), and zinc(锌) contents in the plants, and didn't find any in dangerous levels. In fact, some of these vegetables have lower levels of heavy metals than those grown in regular potting soil. The plants were also tested for vitamins, alkaloids(生物碱), and flavonoids(类黄酮), with good results. While there are six more crops to test, Wamelink himself said that the results up to now are “very promising.”

    “Growing food locally is especially important to our mission of permanent settlement, as we have to ensure sustainable food production on Mars. The results of Dr. Wamelink and his team at Wageningen University & Research are significant progress towards that goal,” said Mars One co-founder and CEO Bas Lansdorp in a press release.

    A crowdfunding campaign is underway (and will be until the end of August) to fund the test of the remaining crops, potatoes included. If all the crops test out safe, with concentrations of heavy metal the FDA and the Dutch Food Agency consider as safe, Wamelink's team will host a “Martian dinner” at the Wageningen greenhouse. But I've seen the movie. Stay clear of the potatoes.

    Whether you prefer burning the midnight oil or going to bed early so you can get up at the break of dawn depends on your genes, according to experts.

    I jump out of bed each morning, eager to start an active day. But I can hear my neighbor's alarm clock ringing non-stop every morning and I doubt he gets to work on time.

    A lot of noise comes from his flat in the evening. He's happy to stay up watching TV till after midnight, while I go to bed early and try to sleep.

    Well, it might not be his fault after all. I'm called“a lark (百灵鸟)”and my neighbor“an owl (猫头鹰)”

    We all have inside “clocks”in the brain to control all kinds of bodily functions and it is reset every day by light. These inside clocks run to a different schedule in “larks” and “owls”. If you have a fast clock, you like to do things early, and if you have a slow clock, you like to do things late.

    Because we live in a 24/7 world, scientists believe it's important to understand a person's “chronotype?—the time of the day when they function the best. It could help us lead a healthier life.

    A US professor has studied sleeping patterns and thinks work times should be changed and made more individual to fit in with our chronotypes.

    And he has advice for those who can't choose their working hours:“If that's not possible, we should be more careful about light exposure,” says the professor. “You should try to go to work not in a covered vehicle but on a bike. The minute the sun sets we should use things that have no blue light, like computer, screens and other electronic devices.”

    In modern society, it is usually considered good to be an extroverted(外向的) person. This means that life can be hard for introverted people. Their talents and abilities are often not recognized.

    Some people often try to make introverts more outgoing. They think that being an introvert is a problem. But there is nothing wrong about being an introvert. Introverts are not necessarily afraid of meeting and talking to others. They simply prefer to spend time on their own, away from the crowds. They like reading, writing and taking walks in the countryside. But extroverts need other people. If they spend a lot of time on their own, they get bored. They tend to be impulsive and talk a lot.

    Our society puts a lot of pressure on people to be extrovert, to be outgoing and self-confident on every occasion. Susan Cain, the author of the book Quiet: The Power of Introverts in a World That Can't Stop Talking, has spoken about this problem. "I was nine years old," Cain says. "In my suitcase there were lots of books. This seemed normal to me, because in our family we always read a lot. I thought it would be the same at summer camp. But I was wrong. To create camp spirit, all the children had to sing a cheer every morning. I couldn't understand why. In the evening, I took out a book from my suitcase. But another girl said, 'why are you being so quiet?' The second time I took out a book, the counselor(辅导员) came to see me. She told me to remember the camp spirit and that it was important to be outgoing."

    At work, extroverts often do well. At job interviews, it is usually good to appear extrovert. It suggests that you will be good at the job. But it is wrong to think that only extroverts are good leaders. Introverts work in different ways to extroverts, but they can still do really great things. Darwin, for example, was a quiet, family man. He often took long walks so that he could think clearly. But Darwin's ideas about evolution were revolutionary.

    Introverts must understand that it is perfectly okay to be the way they are. It is not necessary to want to be the center of attention. You don't have to take part in noisy, social activities if you don't want to. And it is not necessary to try to become more outgoing.

    If we want to find out what kind of technology people used in the past, we normally have to rely on archaeologists to find ruined buildings and parts of tools or instruments or machines. Archaeologists then try to reconstruct, sometimes with the help of computer technology, what these ancient buildings and objects must have looked like, and how they might have been made. Sometimes historians are lucky and find an ancient document with a written description of these ancient buildings and objects.

    We can understand, then, why Chinese historians were so excited when they found cave paintings which show ancient science. They found these paintings in the world-renowned Mogao Grottoes of Dunhuang City, in Northwest China's Gansu Province. There are 500 man-made caves and they have survived for at least 1,600 years. Almost all of these caves have paintings on their ceilings or walls and they date from the 4th to 14th centuries. Wang Jinyu is an expert on these cave paintings (also called frescoes) and he says: "We discovered frescoes containing scientific and technological content in almost all of the caves which have frescoes." What is remarkable about these cave paintings according to the Xinhua News Agency is that they provide evidence of "scientific and technological inventions by ancient Chinese in maths, physics, chemistry, astronomy, geography, agronomy, architecture, textiles, traffic and transportation, arms and military equipment and medical sciences".

    Among the discoveries experts have made are cave paintings showing ancient techniques of pottery making and wine production and paintings showing ancient weaving machines and then toothbrushes! The paintings also give some evidence of the lifestyle at the time with, for example, pictures of people boiling milk over 1,000 years ago. Experts believe that there is more evidence to be found, but even now the caves are a wonderful natural museum. If the walls and ceilings of the caves were all put together they would form a tapestry 20 kilometers long and 2 meters high!

    It won't be possible to travel back in time-that only happens in films-but visiting these caves would be the nearest experience you could get to travelling back in time.

    Triple Olympic and world sprint(短跑) champion Usain Bolt of Jamaica said on Monday he expects years of fast feats to ease doping doubts in athletics and has no plans to play American football.

    Appearing on ESPN programs and in light-hearted races outside the television sport network's studios, Bolt said he feels he must prove himself to a skeptical sports world in the wake of past doping scandals(诽谤).

    "I have to prove myself to the world that you can run fast without it," Bolt said.

    Bolt cited the speeds he and countryman Asafa Powell and American Tyson Gay have achieved without positive doping tests.

    "We just (have to) continue to run fast," Bolt said. "In a couple of years everyone will continue to watch again and have less doubts."

    Bolt won gold in the 100m, 200 and 4x100 relay in world record times at last year's Beijing Olympics and last month in Berlin set world records of 9.58 seconds in the 100 and 19.19 in the 200 and helped a relay title in a World Championships treble.

    "I want to be a legend in the sport. For me it's all a focus on winning championships after championships," Bolt said.

    "I don't consider myself a legend. When I defend my titles I will consider myself a legend."

    Bolt's defending of World and Olympic gold should be the feature attraction of the 2011 IAAF World Championships in Daegu, South Korea, and the 2012 London Olympics.